1. Field of the Invention
The present invention is directed to a search system and search method that includes query refinement, and to such a system and method including a user interface for facilitating user refinement of a search query.
2. Description of Related Art
Electronic searching across large document corpora using a search engine is one of the most broadly utilized applications on the Internet. One fundamental search technique used is the keyword-index search that revolves around an index of keywords from eligible target items. In this method, a user's inputted query is parsed into individual words (optionally being stripped of some inflected endings), whereupon the words are looked up in the index, which in turn, points to documents or items indexed by those words. Thus, the potentially intended search targets are retrieved. This sort of search service by a search engine is accessed countless times each day by many millions of computer and Internet users, and is the basis of the Internet search services provided by Lycos®, Yahoo®, and Google®.
Two main problems of keyword searches are (1) missing relevant documents (i.e. low recall), and (2) retrieving irrelevant ones (i.e. lack of precision). Most keyword search results obtained by a search engine do plenty of both. In particular, with respect to the first problem, the primary limitation of keyword searches is that, when viewed semantically, keyword searches can skip about 80% of the eligible documents because, in many instances, at least 80% of the relevant information will be indexed in entirely different words than words entered in the original query. Granted, for simple searches with very popular words, and where relevant information is plentiful, this is not much of a problem. But for longer queries, and searches where the relevant phrasing is hard to predict, results can be disappointing.
When irrelevant or inadequate search results are retrieved by the search engines in response to the submitted search query, the user typically expands and refines the search query. This is generally accomplished by manually deleting, adding, and/or replacing words in the original query, which all requires the user to manually type in such changes into the search field of the search engine. This also requires to the user to determine, look up, or guess, which terms in the original search query should be modified or replaced in order to obtain better search results from the search engine. Of course, further reformulated search queries may be required over and over again, in order to have the search engine ultimately retrieve the desired documents. This need for reformulating the search query is a common source of frustration for users of search engines who initially thought that the desired documents would be retrieved readily from their initial search query submitted.
The need for reformulating the search query is caused by the fact that the desired documents will have content with substantially the same meaning as the user's entered search query, but which are expressed in different grammar or using different vocabulary. Users can recognize instantly the relevance of such divergent expressions, but machines such as computer implemented search engines acting on the basis of matching keywords cannot make even the most common-sense determinations of sameness of meaning, even when the search query terms are enhanced with wildcards, spelling corrections, and stemming.
For example, a travel website containing a large database of hotel information that is well-structured, with tens of thousands of items, currently cannot determine that “hotel with activities for kids” is the same in meaning as “resort offering a recreation program for children”. However, users could make that determination easily and instantly, even if the user possesses little knowledge of the travel industry. Because of the limitations of machines such as computers and software, the users submitting the search query have the task of reformulating queries in alternative ways rather than machines.
Therefore, there exists an unfulfilled need for a search system and method with query refinement that addresses the above noted limitations and disadvantages of conventional search engines and search methods. In particular, there exists an unfulfilled need for a search system and method that reduces the need for user's typing to delete, add, and/or replace the query words to refine the search query. In addition, there exists an unfulfilled need for such a search system and method which utilizes a user interface that supports, and does not detract from, the search task.